7 Programming FCs (Functions) and FBs for S7 Ethernet CPs
A-237
S7-CPs for Industrial Ethernet Configuring and Commissioning
Release 01/2007
C79000-G8976-C182-07
Status Codes during CP Startup
With a complete restart or restart of the PROFINET CP (after activating a switch
on the module), the output parameters of the block are reset as follows:
DONE = 0
ERROR = 0
STATUS = 8181
H
Time-driven call - recommendation on application
If your application requires time-driven transfer of the CBA data instead of cyclic or
event-driven processing, we recommend the following procedure to call the FB88 /
FB90 blocks.
If you use a time-driven call, remember that the block must be called repeatedly
after it has been started until the DONE flag is set. To allow the CBA data to be
copied between the CPU and CP without any longer interruptions, the follow-on
calls should be as fast as possible and independent of the timing.
Note the following recommendations for programming:
The timing is provided by a timer OB; The timer OB should only cause the first
call for the PROFINET CBA blocks FB88 or FB90 not by calling the block
directly but, for example, by setting a start flag.
The call of the PROFINET CBA blocks FB88 and FB90 should then always be
made in OB1; OB1 starts the call as soon as the start flag is set by the timer
OB.
After the first block call, this is repeated in OB1 until the DONE bit is set (or
until an error occurs); the start flag must then be reset.
Result:
The CBA user data can be copied between the CPU and CP without any
significant interruption thanks to separating the timer OB from the actual block calls
in OB1. You can select the interval between the first calls depending on the
requirements of your application.
FB88 PN_InOut / FB90 PN_InOut_Fast - continued
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